Electrolytic capacitor with improved volumetric efficiency

ABSTRACT

Surface mount electrolytic capacitors are provided with anode and cathode terminations having respective first termination portions provided on the bottom surface of a molded package in a generally coplanar configuration. A second cathode termination portion is bent in a generally perpendicular fashion to the first cathode termination portion and may then be adhered to the external cathode layer of a capacitor body. A second anode termination portion is bent in a generally perpendicular fashion to the first anode termination portion and may then be welded to an anode wire connected to and extending from the capacitor body. An insulation pad may be provided between the first anode termination portion and the capacitor body to prevent device shorting. A planar termination frame may be provided to form the electrolytic capacitors of the present subject matter. Additional embodiments of the disclosed technology include additional termination portions to effect wrap-around surface-mount anode and cathode terminations.

FIELD OF THE INVENTION

The present subject matter generally relates to electrolytic chipcapacitors, and more particularly relates to an electrolytic chipcapacitor with terminations located generally on a bottom surface of thedevice and with a packaged configuration that facilitates increasedvolumetric efficiency and a corresponding potential for a slim capacitorprofile. The present subject matter equally relates to a method forforming such electrolytic capacitors.

BACKGROUND OF THE INVENTION

Electrolytic capacitors, such as tantalum capacitors, are traditionallyknown for their high capacitance value and compactness. Despite theexisting compactness of known electrolytic capacitors and electrolyticcapacitor arrays, there are constant efforts to reduce the volume andcorresponding volumetric efficiency of such electronic components.

Essential components of a conventional electrolytic capacitor include amain capacitor body, an anode wire, and a leadframe all molded togetherin an encapsulating resin package. The volumetric efficiency of anelectrolytic capacitor is typically defined as the ratio of the maincapacitor body volume to the volume of the entire molded capacitorpackage. The anode wire and leadframe of such capacitors form respectivepositive and negative electrical connections to the capacitor structure.These electrical connections typically extend axially from the capacitorstructure, and often take up a significant amount of space inside thecapacitor package.

Many known technological endeavors have addressed the desire fortantalum or other types of electrolytic capacitors with improvedvolumetric efficiency. U.S. Pat. No. 6,400,556 (Masuda et al.) disclosesa solid electrolytic capacitor with eliminated redundant space, improvedvolumetric efficiency and a low profile. U.S. Pat. No. 5,198,968(Galvagni) concerns a compact surface mount tantalum capacitor with highcapacitance per volume.

The prevalent desire to reduce the component size of electrolyticcapacitors becomes even more advantageous when such capacitors areemployed in circuit board applications. Thus, chip-type electrolyticcapacitors, an example of which is disclosed in U.S. Pat. No. 6,017,367(Nakata), have been designed not only with volumetric performancecharacteristics in mind, but also such that device mounting to asubstrate is facilitated. Such facilitated device mounting is oftenachieved by configuring both electrical terminations to extend from aselected surface of the capacitor. Examples of this technology can befound in U.S. Pat. No. 4,107,762 (Shirn et al.), U.S. Pat. No. 4,017,773(Cheseldine) and U.S. Pat. No. 3,789,274 (Pfister).

When both device terminations extend to a selected surface of achip-type capacitor, it is often desirable to provide such electricalconnections in a generally coplanar fashion. A coplanar terminationarrangement may facilitate device mounting to a substrate and may alsohelp to maintain uniformity of certain electrical characteristics of thedevice. U.S. Pat. No. 5,198,968 (Galvagni) discloses a surface mounttantalum capacitor with coplanar terminations. Similarly, U.S. Pat. No.6,236,561 (Ogino et al.) discloses an exemplary chip type capacitor withexposed anode and cathode portions flush with a surface of the capacitordevice such that dual terminations are provided in a generally coplanararrangement. This particular configuration is also intended to increasecapacitor volume.

While examples of various aspects and alternative embodiments are knownin the field of electrolytic capacitors, no one design is known thatgenerally encompasses all of the above-referenced and other preferredcapacitor characteristics.

The disclosures of foregoing United States patents are hereby fullyincorporated into this application for all purposes by referencethereto.

BRIEF SUMMARY OF THE INVENTION

The present subject matter recognizes and addresses various of theforegoing drawbacks and other shortcomings encountered in the prior artof electrolytic capacitor technology. Thus, broadly speaking, aprincipal object of the presently disclosed technology is to provide animproved electrolytic capacitor with coplanar terminations on a selectedsurface of a capacitor chip.

Another principal object of the present subject matter is to provide asurface mount electrolytic capacitor with improved volumetricefficiency. Such improved volumetric efficiency enables certainembodiments of the present subject matter to be formed with reduced casesizing and a slim profile, such as less than about 0.050″ in someembodiments.

A still further object of the present subject matter is to provideversatile termination options such that certain embodiments of thepresent technology may include termination portions that are generallyconfigured along a bottom surface of a capacitor device, but that mayalso wrap around to adjacent sides of the device.

The present subject matter equally concerns methodology for formingsurface mount electrolytic capacitors with improved volumetricefficiency. Such methodology affords simplified process steps and alsohelps ensure that the anode and cathode terminations of the presentsubject matter are provided in a coplanar relationship to the moldedpackage.

Additional objects and advantages of the present subject matter are setforth in, or will be apparent to those of ordinary skill in the artfrom, the detailed description herein. Also, it should be furtherappreciated by those of ordinary skill in the art that modifications andvariations to the specifically illustrated, referenced, and discussedfeatures and steps hereof may be practiced in various embodiments anduses of this invention without departing from the spirit and scopethereof, by virtue of present reference thereto. Such variations mayinclude, but are not limited to, substitution of equivalent means andfeatures, materials, or steps for those shown, referenced, or discussed,and the functional, operational, or positional reversal of variousparts, features, steps, or the like.

Still further, it is to be understood that different embodiments,especially different presently preferred embodiments, of this inventionmay include various combinations or configurations of presentlydisclosed features, steps, or elements, or their equivalents (includingcombinations of features or steps or configurations thereof notexpressly shown in the figures or stated in the detailed description).

Some embodiments of the present subject matter provide for a surfacemount electrolytic capacitor comprising a capacitor body, an anodetermination, a cathode termination and a molded package. A capacitorbody in accordance with the disclosed technology may comprise an anodebody and an anode wire having a first end provided in connection to theanode body and a second end extending therefrom. The anode wire thusforms a first electrical connection for the electrolytic capacitor. Theanode body may then be substantially surrounded with at least oneintermediate layer, such as an oxide layer and an electrolyte layer inone exemplary embodiment. A cathode layer then preferably surrounds theintermediate layer(s) to provide a second electrical connection for theelectrolytic capacitor. The resultant electrolytic capacitor body may begenerally rectangular in shape and characterized by respective top andbottom surfaces.

Anode and cathode terminations in accordance with such exemplaryelectrolytic capacitor embodiments respectively include at least firstand second portions. The first anode and cathode termination portionsare preferably configured in a generally coplanar relationship, in aplane that is generally parallel to the top and bottom surfaces of thecapacitor body. The second anode termination portion may be positionedin a generally perpendicular direction to the first anode terminationportion and provided in electrical connection to the anode wire of thecapacitor body. The second cathode termination portion may be positionedin a generally perpendicular direction to the first cathode terminationportion and provided in electrical connection to the cathode layer ofthe capacitor body. A generally rectangular molded package may thenencapsulate the electrolytic capacitor while exposing the first anodetermination portion and the first cathode termination portion. Theseexposed first termination portions ultimately effect surface mountelectrical connection to the electrolytic capacitors.

In still further electrolytic capacitor embodiments of the presentsubject matter, the anode and cathode terminations may also includerespective third and fourth termination portions to effect wrap-aroundsurface mount terminations. Third and fourth anode termination portionsare provided in a generally perpendicular direction to the first anodetermination portion, while third and fourth cathode termination portionsare provided in a generally perpendicular direction to the first cathodetermination portion. In some more particular embodiments, the third andfourth anode termination portions are both provided along a singleselected side surface of the molded package, and the third and fourthcathode termination portions are also both provided along a singleselected side surface of the molded package, whereby such first andsecond selected side surfaces may oppose one another. In other moreparticular embodiments, the third and fourth anode termination portionsare provided along opposing respective side surfaces, while third andfourth cathode termination portions are similarly provided alongopposing respective side surfaces.

The present subject matter equally concerns methodology for formingsurface mount electrolytic capacitors having a generally rectangularencapsulated body with first and second terminations provided in agenerally coplanar arrangement with a selected surface of theencapsulated body. A first exemplary step in such methodology maycorrespond to providing a generally planar termination frame defined byat least first and second anode termination portions and first andsecond cathode termination portions. The second cathode terminationportion may be bent to be generally perpendicular to the first cathodetermination portion, at which point a capacitor body may be adhered tothe cathode termination via conductive epoxy or other adhesive material.The second anode termination portion may be bent to be generallyperpendicular to the first anode termination portion and to be providedin electrical connection with an anode wire extending from the capacitorbody. The connected anode wire and second anode termination portion maybe welded together to ensure connection. The capacitor body may then beencapsulated in a molded resin package.

Additional methodology in accordance with the disclosed technologyconcerns the formation of surface mount electrolytic capacitors withwrap-around terminations. Similar to the above-referenced methodology, atermination frame is provided, but has first, second, third and fourthrespective anode and cathode termination portions. The step ofencapsulating the capacitor body may leave respective first, third, andfourth termination portions exposed, such that selected of the third andfourth anode and cathode termination portions may be bent in a generallyperpendicular direction to their respective first termination portions.

Additional embodiments of the present subject matter, not necessarilyexpressed in this summarized section, may include and incorporatevarious combinations of aspects of features or parts referenced in thesummarized objectives above, and/or features or parts as otherwisediscussed in this application.

Those of ordinary skill in the art will better appreciate the featuresand aspects of such embodiments, and others, upon review of theremainder of the specification.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the presentinvention, including the best mode thereof, will be more apparent fromthe following more particular description of the present subject matter,presented in conjunction with the appended figures, in which:

FIGS. 1 a and 1 b illustrate an exemplary known configuration of anelectrolytic capacitor with anode wire and leadframe portions extendingaxially from a molded device package;

FIG. 2 illustrates an exemplary electrolytic capacitor configurationwith anode wire and leadframe portions extending to a bottom surface ofa molded device package in accordance with the present subject matter;

FIG. 3 a illustrates a bottom view of a surface mount electrolyticcapacitor in accordance with the present subject matter;

FIG. 3 b illustrates a first side view of a surface mount electrolyticcapacitor in accordance with the present subject matter;

FIG. 3 c illustrates a second side view of a surface mount electrolyticcapacitor in accordance with the present subject matter;

FIG. 4 a displays an exploded side view with top perspective of a firstexemplary surface mount electrolytic capacitor embodiment of thedisclosed technology;

FIG. 4 b displays a side view with bottom perspective of a firstexemplary surface mount electrolytic capacitor embodiment of thedisclosed technology;

FIG. 5 illustrates an exemplary termination frame for use in accordancewith the first exemplary surface mount electrolytic capacitor embodimentdisclosed in FIGS. 4 a and 4 b;

FIG. 6 a displays a side view with top perspective of a second exemplarysurface mount electrolytic capacitor embodiment of the disclosedtechnology before encapsulation;

FIG. 6 b displays a side view with top perspective of a second exemplarysurface mount electrolytic capacitor embodiment of the disclosedtechnology after encapsulation but before final termination formation;

FIG. 6 c displays a side view with top perspective of a second exemplarysurface mount electrolytic capacitor embodiment of the disclosedtechnology after encapsulation and after final termination formation;

FIG. 6 d displays a side view with bottom perspective of a secondexemplary surface mount electrolytic capacitor embodiment of thedisclosed technology after encapsulation and after final terminationformation;

FIG. 7 illustrates an exemplary termination frame for use in accordancewith the second exemplary surface mount electrolytic capacitorembodiment disclosed in FIGS. 6 a through 6 d, respectively;

FIG. 8 a displays a side view with top perspective of a third exemplarysurface mount electrolytic capacitor embodiment of the disclosedtechnology before encapsulation;

FIG. 8 b displays a side view with top perspective of a third exemplarysurface mount electrolytic capacitor embodiment of the disclosedtechnology after encapsulation but before final termination formation;

FIG. 8 c displays a side view with top perspective of a third exemplarysurface mount electrolytic capacitor embodiment of the disclosedtechnology after encapsulation and after final termination formation;

FIG. 8 d displays a side view with bottom perspective of a thirdexemplary surface mount electrolytic capacitor embodiment of thedisclosed technology after encapsulation and after final terminationformation; and

FIG. 9 illustrates an exemplary termination frame for use in accordancewith the third exemplary surface mount electrolytic capacitor embodimentdisclosed in FIGS. 8 a through 8 d, respectively.

Repeat use of reference characters throughout the present specificationand appended drawings is intended to represent same or analogousfeatures or elements of the presently disclosed electrolytic capacitortechnology.

DETAILED DESCRIPTION OF THE DRAWINGS

The following description is of the best mode presently contemplated forcarrying out the invention. The description is made merely for thepurpose of describing the general principles of the invention. It shouldbe noted that the exemplary embodiments disclosed herein should notinsinuate any limitations of the subject mater. Features illustrated ordiscussed as part of one embodiment can be used on another embodiment toyield a still further embodiment. Additionally, certain features may beinterchanged with similar devices or features not expressly mentionedwhich perform the same or similar function.

The present subject matter generally concerns surface mount electrolyticcapacitors with increased volumetric efficiency. Known electrolyticcapacitor designs, such as illustrated in FIGS. 1 a and 1 b, includeanode wire and leadframe portions that extend axially from a capacitorbody. Such configurations are generally characterized by poor volumetricefficiency.

The present subject matter concerns improved surface mount electrolyticcapacitor technology, which generally provides for terminations thatextend to a bottom surface of a capacitive device, such as depicted inFIG. 2. Such configurations in accordance with the disclosed embodimentsfacilitate reduced-cost formation of an electrolytic capacitor withimproved volumetric efficiency and potential for a slim device profile.The volumetric characteristics enable the use of a larger anode in acomponent package having a given size. Such improved surface mountelectrolytic capacitors offer potential advantages for high reliabilitycircuit applications such as medical implantable, military, andaerospace applications.

A first exemplary embodiment of the subject surface mount electrolyticcapacitor technology is displayed in FIGS. 3 a, 3 b, 3 c, 4 a and 4 b.The specific dimensions disclosed in FIGS. 3 a-3 c, respectively, mayalso be applied to additionally disclosed embodiments of the presentsubject matter. A second exemplary embodiment of the subject surfacemount electrolytic capacitor technology is displayed in FIGS. 6 a-6 d,respectively. Further, a third exemplary embodiment of the presentsubject matter is depicted in FIGS. 8 a-8 d respectively.

The present subject matter also concerns corresponding methodology forforming surface mount electrolytic capacitor embodiments. A specificcomponent that may be utilized in such methodology is a terminationframe, exemplary embodiments of which are disclosed in respective FIGS.5, 7 and 9. Electrolytic capacitor bodies may be positioned with atermination frame, which is then bended or shaped to form generallycoplanar surface mount capacitor terminations.

Now with more particular reference to the drawings, FIG. 1 b displays anexemplary known electrolytic capacitor embodiment 2 with electricalconnections provided in an axial configuration. A significant element ofsuch an electrolytic capacitor is the capacitor body 4. The exemplarycapacitor body 4 illustrated in FIGS. 1 a and 1 b comprises an anodeslug, or anode body, 6 which typically corresponds to a generallyrectangular or cylindrical portion of anodizable material.

Exemplary valve metals or other materials that may be utilized in anodebody 6 include anodizable metals such as Tantalum, Niobium, Titanium,Aluminum, and any alloyed combination of such metals or other valvemetals, anodizable metal nitrides such as Tantalum Nitride and NiobiumNitride, and anodizable metal oxides such as Niobium Oxide. It should beappreciated that many different variations of reduced Niobium Oxides maybe suitable for use in an anode body of the present technology.

An anode wire 8 (also referred to as an anode lead or a lead wire) isutilized to form a first electrical connection to the capacitor body 4.A first end of anode wire 8 is connected to anode body 6 and a secondend extends axially from anode body 6. The first end of anode wire 8 maybe embedded within anode body 6 or it may alternatively be weldedthereto.

A substantial portion of anode body 6 is then preferably coated with atleast one intermediate layer before being coated with a cathode layer10, which provides a second electrical connection for capacitor body 4.In more particular exemplary embodiments of the present subject matter,the intermediate layers provided between anode body 6 and cathode layer10 include an oxide layer 12 and an electrolyte layer 14 (or alternateconductive layer.) A leadframe 16 is then typically positioned incontact with cathode layer 10 to provide an extended electricalconnection to capacitor body 4.

It should be appreciated that additional layers and other features aswould be within the purview of one of ordinary skill in the art ofcapacitor technology may also be included in the formation ofelectrolytic capacitor body 4 while remaining within the spirit andscope of the present subject matter.

Referring to FIG. 1 b, a portion of leadframe 16 may typically beprovided adjacent to capacitor body 4, and then bent at angle of aboutninety degrees such that it extends axially in a generally parallelfashion to anode wire 8. Capacitor body 4, a portion of anode wire 8 anda portion of leadframe 16 are then preferably encapsulated in a moldedresin package 20 that protects the encapsulated elements and securesboth anode wire 8 and leadframe 16 in their resultant axialconfiguration. Anode wire 8 and leadframe 16 may extend axially from thesame selected side of electrolytic capacitor 2 (as shown in FIG. 1 b) orfrom opposing sides. Regardless, electrical connections provided in anaxial fashion typically leave a substantial amount of “unused” roomwithin molded package 20, thus characterizing electrolytic capacitor 2by relatively poor volumetric efficiency.

In accordance with the presently disclosed technology, an improvedtermination arrangement yields greater volumetric efficiency forelectrolytic capacitor designs. Referring to FIG. 2, an exemplaryelectrolytic capacitor 22 includes a capacitor body 4 with leadframe 16and anode wire 8 that extend out of bottom surface 24 of molded package20. Such configuration with bottom terminations provides for a capacitordesign with a volumetric efficiency that nearly doubles that ofexemplary configurations with axial terminations. Providing a capacitorwith bottom terminations in accordance with the present subject matteryields improvements in an ability to mount such a capacitor to a printedcircuit board or other substrate, thus yielding improved “surface mount”electrolytic capacitors.

General aspects of the exemplary capacitor embodiment 22 of FIG. 2 areset forth more particularly in FIGS. 3 a-9, respectively, in accordancewith a detailed description of exemplary embodiments of the disclosedtechnology. FIGS. 3 a-3 c, respectively, illustrate a first exemplaryelectrolytic capacitor embodiment 26 in accordance with the disclosedtechnology, including exemplary dimensions for such electrolyticcapacitor. Although described with respect to first exemplary embodiment26, selected dimensions as displayed in FIGS. 3 a, 3 b and 3 c may alsobe applied to other electrolytic capacitor embodiments in accordancewith the present subject matter.

It should be appreciated that such figures may not be drawn to scale,and that selected elements of each figure may not be represented inproportion to other elements in that figure. It should also beappreciated that for the sake of convenience, FIG. 3 a is referred to asa generally bottom view, FIG. 3 b is referred to as a first side view,and FIG. 3 c is referred to as a second side view. For additionalconvenience, distances between top and bottom portions of electrolyticcapacitor 26 are referenced as height (or profile), distances betweenfirst sides of electrolytic capacitor 26 are referenced as width, anddistances between second sides of electrolytic capacitor 26 arereferenced as length.

Now referring to FIGS. 3 a-3 c, respectively, electrolytic capacitor 26includes a capacitor body 4, with exemplary length 28 of about 0.165″(inches), exemplary width 30 of about 0.100″, and exemplary height 32 ofabout 0.040″, yielding a volume of about 0.00066 in.³ An anode wire 34extends from capacitor body 4, and has an exemplary radius of about0.005″ and a length 36 extending out of capacitor body 4 of about0.030″. A Teflon washer 38 may be placed around the anode wire 34 toprovide additional support for such first electrical connection. Washer38 may have an exemplary diameter 40 of about 0.030″ and an exemplarywidth 42 of about 0.012″. As an alternative to washer 38, a green Teflonpaint or other appropriate coating may be applied to provide additionalsupport for anode wire 34. The applied Teflon paint or other greencoating may be further strengthened upon later firing processes astypically associated with capacitor formation.

A cathode termination serves the function of a conventional leadframeelement, and comprises a first portion 44 and second portion 46. Firstportion 44 is provided in a plane that is generally parallel to the topand bottom surfaces of capacitor body 4, and may be characterized by alength 48 of about 0.035″, a width 50 generally spanning the entirewidth of capacitor 26 (about 0.110″,) and a height 52 of about 0.005″.Second portion 46 of the cathode termination is provided generallyperpendicular to first portion 44, and is adjacent to and in electricalconnection with capacitor body 4. The thickness of second portion 46 isgenerally equivalent to the height of first portion 44, and may have anexemplary height 54 of about 0.025″.

An anode termination is provided to connect to anode wire 34 andpreferably comprises a first portion 56 and a second portion 58. Firstportion 56 is provided in a plane that is generally parallel to the topand bottom surfaces of capacitor body 4, and may be characterized by alength 60 of about 0.035″ and exemplary width and height dimensionssimilar to the first cathode termination portion 44. The second anodetermination portion 58 is generally perpendicular to first anodetermination portion 56 and may be designed to fit around anode wire 34as shown in FIG. 3 c.

A molded package 60 is provided to encapsulate portions of capacitor 26and offer protection for such encapsulated components as capacitor body4, anode wire 34, second cathode termination portion 46 and second anodetermination portion 58. Molded package 60 may have an exemplary length62 of about 0.210″, an exemplary width 50 of about 0.110″ and anexemplary height 64 of about 0.050″, yielding a volume of about 0.001155in.³ Molded package 60 may be formed with respective clearance distances66, 68 and 70 of about 0.005″ each. Distance 72 may be about 0.010″.

It should be appreciated that the specific dimensions presented abovewith respect to FIGS. 3 a-3 c, respectively, provide for an electrolyticcapacitor with a relatively slim profile of about 0.050″. The improvedtermination arrangement of the present subject matter enables a reducedcapacitor profile of 0.050″ or less, but the scope of the presenttechnology should in no way be limited to such reduced profile range. Byemploying a larger anode body and similar clearance range between theanode body, molded package and other elements, an electrolytic capacitorwith a larger profile and also a larger volumetric efficiency may beenabled.

Since volumetric efficiency is defined as the ratio of capacitor bodyvolume to the volume of the molded package, the volumetric efficiency ofthe electrolytic capacitor 26 of FIGS. 3 a-3 c respectively is about57.14%. Alterations to the specific dimensions illustrated in FIGS. 3 aand 3 b, and in particular to the size of the anode body and/or the sizeof the molded package, may yield electrolytic capacitor embodiments withvolumetric efficiency above or below 57.14%. It should be appreciatedthat such potential range for volumetric efficiency of an electrolyticcapacitor in accordance with the present subject matter should at leastbe inclusive of between about 55% to about 60%, and may yield an evenhigher volumetric efficiency in accordance with further embodiments ofthe disclosed technology.

Additional views of first exemplary electrolytic capacitor 26 are shownin FIGS. 4 a and 4 b. FIG. 4 a shows a generally side exploded view withtop perspective and FIG. 4 b shows a generally side view with bottomperspective of exemplary electrolytic capacitor 26. Anode wire 34extends from a selected side of capacitor body 4 and may be providedwith a washer 38 thereon. As previously mentioned, Teflon paint or othercoatings may be substituted for the washer 38. Second anode terminationportion 58 is configured for adjacent position against and electricalconnection to anode wire 34. Second cathode termination portion 46 isconfigured for adjacent position to and electrical connection tocapacitor body 4, and more particularly to the cathode layer thatsubstantially surrounds capacitor body 4.

First cathode termination portion 44 and first anode termination portion56 are both formed in a generally coplanar relationship with one anotherand remain exposed (as shown in FIG. 4 b) after other elements ofcapacitor 26 are encapsulated in molded package 60. Respective firstportions 44 and 56 may both be generally U-shaped in configuration, asis further presented with respect to the termination frame embodiment ofFIG. 5.

Molded package 60 may for example be formed of a thermoplastic orthermoset resin compound that is molded around selected portions ofelectrolytic capacitor 26 to totally encapsulate the capacitor body andportions of the metallized anode and cathode terminations. It should beappreciated that other protective features than encapsulation (e.g.,providing a cover) are within the purview of one of ordinary skill inthe art, and should be considered within the scope of the presenttechnology.

A significant feature of the electrolytic capacitor designs inaccordance with the disclosed technology is that the first anodetermination portion 56 and the first cathode termination portion 44remain in a substantially coplanar relationship with one another andwith a surface of the molded package. Particular methodology associatedwith forming electrolytic capacitors of the present subject matter helpsto ensure such a coplanar relationship. Aspects of such methodology arepresented hereafter with respect to FIG. 5.

FIG. 5 displays an exemplary termination frame 74 that may be used informing electrolytic capacitors in accordance with the present subjectmatter. Termination frame 74 may correspond to a metallized structure,for example one made of stamped electroplated wire, that forms first andsecond respective portions of the anode and cathode terminations.Specific exemplary materials that may be used in forming metallizedtermination frame include OLIN Alloy Nos. 42, 194, 725, 752 or othersuitable termination frame materials. A termination frame typicallyincludes portions for forming a plurality of electrolytic capacitors(for example, three such portions are shown in FIG. 5), and may beutilized with any number of singular or plural component formation.

A first step in forming exemplary electrolytic capacitor 26 whileutilizing exemplary termination frame 74 is to bend up each secondcathode termination portion 46 such that it is in a generallyperpendicular relationship to first cathode termination portion 44.Respective capacitor bodies 4 are then preferably arranged within thetermination frame and adhered to the cathode termination via conductiveepoxy or other appropriate adhesive material as within the purview ofone of ordinary skill in the art. Each second anode termination portion58 is then preferably bent up such that it is in a generallyperpendicular relationship to first anode termination portion 56. Eachsecond anode termination portion 58 preferably contains a semicircularcut-out 76 to accommodate anode wire 34 as second portion 58 and anodewire 34 are configured adjacent to one another. An electrical connectionbetween such adjacent components may then be further facilitated bywelding (e.g, via resistance welding or laser welding techniques) eachanode wire 34 to each second anode termination portion 58.

Additional exemplary steps in the subject methodology for formingelectrolytic capacitors 26 include encapsulating each capacitor body andrespective anode wire and termination portions within respective moldedresin packages. Termination frame 74 can then be diced among distinctcapacitors and respective portions of the terminations thereof such thatmultiple surface mount electrolytic capacitors are effected.

Now referring to FIGS. 6 a-6 d, respectively, a second exemplaryelectrolytic capacitor embodiment 78 in accordance with the presentsubject matter includes surface mount terminations with wrap-aroundfeatures. Referring to FIG. 6 a, a capacitor body 4 is provided with ananode wire 34 embedded therein. An optional washer 38 or alternativefeature may be provided around anode wire 34. An anode terminationcomprises first portion 56 and second portion 58, similar to the anodetermination of capacitor embodiment 26 of FIGS. 4 a and 4 b. The anodetermination of electrolytic capacitor 78 further comprises a third anodetermination portion 80 and fourth anode termination portion 82. Acathode termination comprises first portion 44 and second portion 46,similar to the cathode termination of electrolytic capacitor 26 of FIGS.4 a and 4 b. The cathode termination further comprises a third cathodetermination portion 84 and fourth cathode termination portion 86.

All four portions of each respective anode and cathode terminations areinitially provided in a single flat termination frame 88 as depicted inFIG. 7. The second cathode termination portion 46 is bent up in agenerally perpendicular fashion to first cathode termination portion 44,at which point the cathode termination may be “glued” to the cathodelayer of capacitor body 4. Second anode termination portion 58 may thenbe bent up to be generally perpendicular to first anode terminationportion 56 and adjacent to anode wire 34, at which point the anode wire38 and second termination portion 58 may be welded together.

Referring still to the second electrolytic capacitor embodiment 78 ofFIG. 6 a, an insulation pad 90 may be provided between the first anodetermination portion 56 and capacitor body 4 to provide electricalinsulation and to reduce the possibility of the capacitor body 4shorting out to the anode wire 34. Such insulation pad 90 may be formedof insulation tape or of a insulation material sprayed onto the desiredlocation within capacitor 78. It should be appreciated that theinsulation pad 90 shown with respect to FIG. 6 a may be incorporatedinto the design of any electrolytic capacitor structure of the presentsubject matter, including the first exemplary electrolytic capacitorembodiment 26, and other exemplary embodiments presented hereafter.

After accomplishing the exemplary steps discussed above, a thermoplasticor thermoset resin material may encapsulate portions of capacitor 78 ina molded package 60 as shown in FIG. 6 b. Molded package 60 preferablyleaves part of the first, third, and fourth respective portions of theanode and cathode terminations exposed. First anode termination portion56 and first cathode termination portion 44 are arranged in a generallycoplanar relationship with one another.

After encapsulating selected portions of capacitor 78, the third anodetermination portion 80 and fourth anode termination portion 82 are bentup in a generally perpendicular fashion to first anode terminationportion 56 as shown in FIGS. 6 c and 6 d. Final positioning of suchportions 80 and 82 of electrolytic capacitor 78 are preferablyrespectively provided along opposing surfaces of molded package 60,wherein the selected opposing surfaces are adjacent to the bottomsurface corresponding to first anode termination portion 56. The thirdand fourth anode termination portions 80 and 82 may be secured to moldedpackage 60 via conductive epoxy or other adhesive features.

With further reference to FIGS. 6 c and 6 d, the third cathodetermination portion 84 and fourth cathode termination portion 86 arebent up in a generally perpendicular fashion to first cathodetermination portion 44. Final positioning of such portions 84 and 86 ofelectrolytic capacitor 78 are preferably respectively provided alongopposing surfaces of molded package 60, wherein the selected opposingsurfaces are adjacent to the bottom surface corresponding to firstcathode termination portion 44. The third and fourth cathode terminationportions 84 and 86 may be secured to molded package 60 via conductiveepoxy or other adhesive features. Anode termination portion 80 andcathode termination portion 84 are preferably arranged on the same sideof molded package 60, while anode termination portion 82 and cathodetermination portion 86 preferably reside on another same selected side.

Now referring to FIGS. 8 a-8 d, respectively, a third exemplaryelectrolytic capacitor embodiment 92 in accordance with the presentsubject matter includes surface mount terminations with alternativewrap-around features. Referring to FIG. 8 a, a capacitor body 4 isprovided with an anode wire 34 embedded therein or welded thereto. Anoptional washer 38 or alternative feature may be provided around anodewire 34. An anode termination comprises first portion 56 and secondportion 58, similar to the anode termination of previously discussedelectrolytic capacitor embodiments 26 and 78. The anode termination ofelectrolytic capacitor 92 further comprises a third anode terminationportion 94 and fourth anode termination portion 96. A cathodetermination comprises first portion 44 and second portion 46, similar tothe cathode termination of previously discussed electrolytic capacitors26 and 78. The cathode termination further comprises a third cathodetermination portion 98 and fourth cathode termination portion 100.

All four portions of each respective anode and cathode terminations areinitially provided in a single flat termination frame 102 as depicted inFIG. 9. The second cathode termination portion 46 is bent up in agenerally perpendicular fashion to first cathode termination portion 44,at which point the cathode termination may be “glued” to the cathodelayer of capacitor body 4. Second anode termination portion 58 may thenbe bent up to be generally perpendicular to first anode terminationportion 56 to be adjacent to anode wire 34, at which point the anodewire 38 and second termination portion 58 may be welded together.Insulation tape (as discussed with reference to FIG. 6 a) may beprovided between the first anode termination portion 56 and anode wire34 of electrolytic capacitor 92.

After accomplishing the exemplary steps discussed above, a thermoplasticor thermoset resin material may encapsulate portions of capacitor 92 ina molded package 60 as shown in FIG. 8 b. Molded package 60 preferablyleaves part of the first, third, and fourth respective portions of theanode and cathode terminations exposed. First anode termination portion56 and first cathode termination portion 44 are arranged in a generallycoplanar relationship with one another.

After encapsulating selected portions of capacitor 92, the third anodetermination portion 94 and fourth anode termination portion 96 are bentup in a generally perpendicular fashion to first anode terminationportion 56 as shown in FIGS. 8 c and 8 d. Final positioning of suchportions 94 and 96 of electrolytic capacitor 92 are preferably bothprovided along a single selected surface of molded package 60, whereinthe selected surface is adjacent to the bottom surface corresponding tofirst anode termination portion 56. The third and fourth anodetermination portions 94 and 96 may be secured to molded package 60 viaconductive epoxy or other adhesive features.

With further reference to FIGS. 8 c and 8 d, the third cathodetermination portion 98 and fourth cathode termination portion 100 arebent up in a generally perpendicular fashion to first cathodetermination portion 44. Final positioning of such portions 98 and 100 ofelectrolytic capacitor 92 are preferably both provided along a singleselected surfaces of molded package 60, wherein the selected surface isadjacent to the bottom surface corresponding to first cathodetermination portion 44. The third and fourth cathode terminationportions 98 and 100 may be secured to molded package 60 via conductiveepoxy or other adhesive features. The side of molded package 60 on whichanode termination portions 94 and 96 are provided preferably opposes theside of molded package 60 on which cathode termination portions 98 and100 are provided.

While the present subject matter has been described in detail withrespect to specific embodiments thereof, it will be appreciated thatthose skilled in the art, upon attaining an understanding of theforegoing may readily produce alterations to, variations of, andequivalents to such embodiments. Accordingly, the scope of the presentdisclosure is by way of example rather than by way of limitation, andthe subject disclosure does not preclude inclusion of suchmodifications, variations and/or additions to the present subject matteras would be readily apparent to one of ordinary skill in the art.

1-44. (canceled)
 45. A surface mount electrolytic capacitor comprising:an anode body; a cathode layer substantially surrounding said anode bodyand yielding a capacitor body characterized by a top and bottom surface;an anode lead with a first end connected to said anode body and a secondend extending therefrom; an anode termination that is in electricalconnection with said anode lead, said anode termination comprising afirst portion provided generally parallel to said bottom surface of saidcapacitor body; a cathode termination that comprises a first portion anda second portion, said first portion of said cathode termination beingprovided generally parallel to said bottom surface of said capacitorbody, and said second portion of said cathode termination being providedgenerally perpendicular to said first portion of said cathodetermination, wherein said second portion of said cathode termination isin electrical connection with said cathode layer; and a package thatencapsulates said capacitor body in such a manner that only said firstportion of said anode termination and said first portion of said cathodetermination are exposed.
 46. The capacitor of claim 45, wherein saidanode termination further comprises a second portion that is providedgenerally perpendicular to said first portion of said anode termination.47. The capacitor of claim 46, wherein said second portion of said anodetermination is in electrical connection with said anode lead.
 48. Thecapacitor of claim 47, wherein said second portion of said anodetermination is in electrical connection with said anode lead via a metalweld.
 49. The capacitor of claim 45, wherein said first portion of saidcathode termination is in electrical connection with said cathode layer.50. The capacitor of claim 49, wherein said first portion of saidcathode termination is in electrical connection with said cathode layervia a conductive adhesive.
 51. The capacitor of claim 45, wherein saidsecond portion of said cathode termination is in electrical connectionwith said cathode layer via a conductive adhesive.
 52. The capacitor ofclaim 45, wherein said first portion of said cathode termination has aU-shaped configuration.
 53. The capacitor of claim 45, wherein saidfirst portion of said anode termination has a U-shaped configuration.54. The capacitor of claim 45, wherein a surface of said package issubstantially coplanar with said first portion of said anode terminationand said first portion of said cathode termination.
 55. The capacitor ofclaim 45, wherein said package is generally rectangular.
 56. Thecapacitor of claim 45, further comprising an insulation pad positionedbetween said first portion of said anode termination and said capacitorbody.
 57. The capacitor of claim 45, further comprising a washer thatgenerally surrounds said anode lead.
 58. The capacitor of claim 45,wherein said first end of said anode lead is embedded within said anodebody.
 59. The capacitor of claim 45, wherein said first end of saidanode lead is welded to said anode body.
 60. The capacitor of claim 45,wherein the profile of the capacitor is less than about 0.050 inches.61. The capacitor of claim 45, wherein the volumetric efficiency of thecapacitor is at least about 50 percent.
 62. The capacitor of claim 45,wherein said capacitor body further comprises at least one additionallayer between said anode body and said cathode layer.
 63. The capacitorof claim 62, wherein said additional layer is an oxide layer.
 64. Thecapacitor of claim 45, wherein said anode body comprises tantalum. 65.The capacitor of claim 45, wherein said anode body comprises niobium.66. The capacitor of claim 65, wherein said anode body comprises anoxide of niobium.
 67. The capacitor of claim 45, wherein said anode bodycomprises aluminum or titanium.
 68. A surface mount electrolyticcapacitor comprising: an anode body; a cathode layer substantiallysurrounding said anode body and yielding a capacitor body characterizedby a top and bottom surface; an anode lead with a first end connected tosaid anode body and a second end extending therefrom; an anodetermination that comprises a first portion provided generally parallelto said bottom surface of said capacitor body, and a second portionprovided generally perpendicular to said first portion of said anodetermination, wherein said second portion of said anode termination is inelectrical connection with said anode lead; a cathode termination thatcomprises a first portion and a second portion, said first portion ofsaid cathode termination being provided generally parallel to saidbottom surface of said capacitor body, and said second portion of saidcathode termination being provided generally perpendicular to said firstportion of said cathode termination, wherein said first and secondportions of said cathode termination are in electrical connection withsaid cathode layer; and a molded resin package that encapsulates saidcapacitor body in such a manner that only said first portion of saidanode termination and said first portion of said cathode termination areexposed, wherein a surface of said package is substantially coplanarwith said first portion of said anode termination and said first portionof said cathode termination.
 69. The capacitor of claim 68, wherein saidfirst portion of said cathode termination has a U-shaped configuration.70. The capacitor of claim 68, wherein said first portion of said anodetermination has a U-shaped configuration.
 71. The capacitor of claim 68,wherein said capacitor body comprises an oxide layer between said anodebody and said cathode layer.
 72. The capacitor of claim 68, wherein saidanode body comprises tantalum.
 73. The capacitor of claim 68, whereinsaid anode body comprises niobium.
 74. The capacitor of claim 73,wherein said anode body comprises an oxide of niobium.
 75. The capacitorof claim 68, wherein said anode body comprises aluminum or titanium. 76.A surface mount electrolytic capacitor comprising: an anode body,wherein said anode body comprises at least one metal selected from thegroup consisting of tantalum, niobium, aluminum, and titanium; an oxidelayer; a cathode layer substantially surrounding said anode body andsaid oxide layer, and yielding a capacitor body characterized by a topand bottom surface; an anode lead with a first end connected to saidanode body and a second end extending therefrom; an anode terminationthat comprises a first portion provided generally parallel to saidbottom surface of said capacitor body, and a second portion providedgenerally perpendicular to said first portion of said anode termination,wherein said second portion of said anode termination is in electricalconnection with said anode lead; a cathode termination that comprises afirst portion and a second portion, said first portion of said cathodetermination being provided generally parallel to said bottom surface ofsaid capacitor body, and said second portion of said cathode terminationbeing provided generally perpendicular to said first portion of saidcathode termination, wherein said first and second portions of saidcathode termination are in electrical connection with said cathodelayer; and a molded resin package that encapsulates said capacitor bodyin such a manner that only said first portion of said anode terminationand said first portion of said cathode termination are exposed, whereina surface of said package is substantially coplanar with said firstportion of said anode termination and said first portion of said cathodetermination.